Dark matter density profiles of the Milky Way satellite population: Reconciling simulations and observations

The cusp-core problem remains a central challenge in the Λ cold dark matter model. Comparisons between the inner logarithmic slopes (dłog̊ho/dłog r) of dark matter haloes of galaxies inferred from simulations and observations have historically suffered from a systematic methodological mismatch. Comparing slopes at different radii raised apparent tensions between simulations and observations due to inconsistent slope definitions rather than genuine physical discrepancies. Our aim was to perform a rigorous comparison between dark matter density profiles of Milky Way dwarf satellite galaxies inferred from dynamical modelling and those predicted by cold dark matter cosmological hydrodynamical simulations in order to evaluate their agreement. We used the NIHAO and FIRE-2 cosmological zoom-in simulation suites (M_⋆ ∼ 10^3--10^ 11 ,̊m M_⊙) to compare simulated dark matter density profiles against dynamical model inferences of 16 Milky Way satellites from four distinct methods, restricting the analysis to their reliability limits. We evaluated simulated slopes at observationally accessible radii and directly compared full density and slope profiles between simulated and observed satellites of matched stellar mass. The observed and simulated galaxies revealed a clear mass-dependent core-formation trend, with inner slopes rising from super-cuspy values (dłog̊ho/dłog r ≈ -1.5) at $M_⋆ ∼ 10^5,̊m M_⊙$ to core-like values (≈ 0 to -0.4) at $M_⋆ 10^8,̊m M_⊙$. Efficient core formation begins at M_⋆ ≳ 10^6,̊m M_⊙, with satellite systems presenting increased scatter at this mass, consistent with tidal disruption. Simulated profiles agree with observations to within $łesssim 1σ$ for most systems, outperforming a Navarro-Frenk-White profile. Willman,1 remains an unresolved outlier whose anomalous structural properties are not reproduced by either simulation suite. Observational models present scatter for the same system at a level comparable to the apparent simulation-to-observation offset. Evaluating dark matter density slopes at fixed physical radii significantly improves the agreement between hydrodynamical simulations and dynamical models of dwarf satellites. Moreover, a comprehensive comparison of full density profiles at a fixed stellar mass presents no clear signs of tension.